Installations for sucking off and separation of waste products of working machines and centrifugal air pumps for use with it



June 17, 1969 C.'N|HOT ET AL 3,450,333

INSTALLATIONS FOR SUCKING OFF AND SEPARATION OF WASTE PRODUCTS OF WORKING MACHINES AND CENTRIFUGAL -AIR PUMPS FOR USE WITH IT Filed Jan. 23. 1967 J 4 INVENTOR D ouaamg ATTORNEY United States Patent 3,450,333 INSTALLATIONS FOR SUCKING OFF AND SEPA- RATION OF WASTE PRODUCTS OF WORKING MACHINES AND CENTRIFUGAL AIR PUMPS FOR USE WITH IT Casper Nihot, Pieter Borstraat 36, Amsterdam, Netherlands; Evert Rudolf Nihot, Vinkenstraat 2, Zandvoort, Netherlands; and Petrus Andr Hnri Saueressig, G. van Amstellaan 47. Amstelveen, Netherlands Filed Jan. 23, 1967, Ser. No. 611,004 Claims riority, application Netherlands, Jan. 28, 1966, 6601163 Int. Cl. F04c 29/00; F04d 29/00; B01d 45/14 US. Cl. 23047 5 Claims ABSTRACT OF THE DISCLOSURE An installation for aspirating and separating waste products of working machines, especially wood working machines, with the assistance of air as a transporting medium and driven by a centrifugal air pump or exhauster functioning as a suction and pressure pump behind which a separation occurs in apart of the air with the relatively heavy waste products which are conveyed to storage and the remainder via a dust filter and from which the air can be recovered. A spiral-shaped widening delivery channel of the pump is extended beyond the beginning thereof to such a degree that the particles to be separated and displaced outwardly at such location also can separate and group together according to their weight so that the separation of the quantity of the air containing the relatively heavy waste products occurs in the outlet of the centrifugal air pump.

The invention relates to an installation for aspirating and separating the waste products of working machines, and more particularly wood working machines, with the aid of air as a transport medium, which is driven by means of a centrifugal air pump or exhauster working as suction and pressure pump, and behind which a separation takes place in a part of the air with the relatively heavy waste products, which are carried off to a store room, with the rest being transported through a dust filter and from which the air can recovered.

Such an installation is already known.

The loss of the transport air is undesired, especially in the cold seasons, because such air is withdrawn from the work room at the working machines and therefore in cold seasons such air in the main will be heated air. If this air is withdrawn from the 'work room and replaced by fresh atmospheric air, the fresh air must initially be brought to the right temperature again thereby involving high costs for the space heating. It is therefore important to keep at a minimum the percentage of transport air which is lost, without obstacles being encountered in the neighborhood as a consequence of impurities in the air carried along with the lost transport air. For achieving this end with the known installation, the relatively heavy waste products are separated from the air stream leaving the exhauster to the greatest extent possible in a separate =preseparator appliance functioning as a type of cyclone separator, after which this part of the air is immediately carried away with the waste products to a store room, which at the same time serves as a sink room, or through an endseparator constituted by a cyclone separator. The separate pre-separator is a device which is specially developed for this purpose and has to work the whole quantity of air passing therethrough and is therefore relatively large and expensive thus augmenting the costs of the installation. Furthermore, with the known installation, the parts are necessarily built up near one another which is a drawback in many cases in view of the necessary space.

The object of the invention is to overcome these drawbacks.

According to the invention this is obtained in that the spiral-shaped widening delivery channel of the pump extends beyond the beginning thereof to such an extent that the particles to be separated and displaced at such location can separate and group together according to their weight, that the separation of the quantity of the transport air containing the relatively heavy waste products take place in the outlet of the centrifugal pump. In this construction there already occurs in the outlet of the centrifugal air pump or exhauster a separation of the waste products from the transport air to a great extent by the existing centrifugal forces, since the waste products are concentrated in the outermost layer of the passing air stream. Hence, a separate separator can be avoided, so that the whole installation is particularly simple. In addition, the waste products thereafter can be further separated from the transport air in a small cyclone separator and carried away to a store room, while the transport air which no longer contains objectionable impurities can be passed directly into the atmospheric air without causing any inconvenience. The rest of the air is conducted through a dust filter in usual manner and returned to the work room and recovered in a known manner. In practice the installation performs in such a manner that in the outlet of the centrifugal air pump a separating wall is provided near the outer wall, which wall separates a small portion of the passing air stream flowing along the outer wall of the pump and which contains the most impure air. This impure air can then be carried away in a known manner to the store room or a similar waste collecting room, to the air delivery of which a (cyclone) separator is connected, which, in view of the small amounts of air to be treated, need not be large. The store room with the separator can, in this case, be built up quite independently of the exhauster, at an adequate location similar to the small dust filter necessary for cleaning the air to be returned to the work room.

In practice, the separating wall is further advantageously arranged in such a manner that it leads an amount of about 10-25%, preferably of about 15-20%, along the outer wall of the centrifugal air pump to the final separator. The loss of heated air is then limited to the percentages mentioned, which are known in this order of magnitude. In order to adapt the amount of transport air to the circumstances for a good result, the separating wall is preferably extended at the free end which is directed inwardly with a hinged adjustable baffle. By adjusting the bafile with its free end edge closer or farther from the outer wall, the amount of separated transport air can be adjusted and at the same time the nature of the impurities to be removed can be taken into account, so that all or practically all relatively large impurities are removed. The fine impurities can be carried off with the main mass of the passing transport air to the dust filter. Experiments have shown that only a small dust filter suffices for this purpose and has to work such a small amount of dust that under definite conditions it must be cleaned but once a month, or even after a still longer period. It appears that by the centrifugal force in the centrifugal air pump practically all impurities, with the exception of a small portion of very fine dust-like im purities, are thrown to the outer wall of the pump housing and are carried away with that portion of the transport air which is delivered to the end separator.

The invention also comprises the centrifugal air pump to be used with the above described installation, and which pump is appropriately formed so that the pump housing possesses a spiral-shaped widening delivery channel extending more than 360, and in the outlet of which, in

the part lying beyond the begining of the delivery channel, at a relatively small distance from the outer wall of the housing a separating wall is arranged, whereby a definite percentage of the air stream passing along the outside is separated from the remainer.

In practice, the pump is preferably constructed in such a manner that the separating wall can separate about 1025% of the amount of air passing along the outside.

A particularly favourable construction of the centrifugal air pump or exhauster is obtained if the delivery channel extends about 450 around the spindle of the pump rotor and the outer wall is continued tangentially some distance so that between this tangential end portion and the bent outer wall of the delivery channel lying at the inside thereof a widening outlet of the delivery channel is provided, and across which a bridge strip is fixed supporting the separating wall. Thus, it can be obtained with certainty that the relatively heavy waste products have had the opportunity to move to the outer wall of the pump housing and that in the parts near the separating wall no new admittance of air with impurities can occur any longer in a radial direction. Moreover, the separating wall in the widening mouth of the outlet of the air pump housing serves for enabling the establishment of good connections of the further separated air streams via bridging strip without the total cross-sectional area of the outlet of the air pump being reduced.

Furthermore, the pump is perferably formed in such a manner that the separating wall is provided at the inner end with a hinged extension, which is adjustable from the outside, whereby the amount of air delivered along the outside can be further adjusted.

In addition, the air pump is preferably constructed in such a manner that the real starting point of the spiral shaped delivery channel is displaced at an angle of about 35-50 in the direction of the air stream with respect of the theoretical starting 'point. Consequently, it is avoided with certainty that the separation could be affected by relatively large and/or large impurities thrown directly into the outlet by the pump rotor.

The invention will now be described With reference to an embodiment of the invention shown in the drawing and in which drawing:

FIG. 1 is a view in side elevation of a centrifugal air pump or exhauster according to the invention, and

FIG. 2 is a view in front elevation of the outlet side of the pump illustrated in FIG. 1.

In the drawing, 1 is a pump spindle of a centrifugal air pump which is driven by an electric motor 2 mounted on a bracket 3 located beside a pump housing 4. In the pump housing 4, the spindle 1 extends through a bearing sleeve 5 and carries a pump rotor 6, which is provided with radial blades of the desired configuration. Opposite to the rotor 6 and co-axial therewith is an opening 7 in the housing 4 for the introduction of the pump rotor. The edge of the opening 7 is provided with an internal reinforcing ring 8 and the opening can be closed by a cover 9 having a central inlet opening to which a main suction line 11 is connected. The line 11 is provided with branch pipes (not shown) in the usual manner which lead to the suction locations at the working machines. By these suction pipes and the main suction line 11, 'air from the work room which serves as a transport medium and contains waste products, which can vary from very fine dust to relatively large wood particles and small wooden splinters, is transported to the pump rotor 6 and from such rotor is blown into a spiral-shaped widening delivery channel of the centrifugal air pump. The delivery channel is of rectangular cross-section in that the housing 4 is defined by two flat side wall plates 4a and 4b which extend perpendicular to the rotor spindle 1 on both sides thereof and between which a spiral-shaped outer Wall 12 of the delivery channel is arranged.

The wall 12 begins theoretically about at the level of a horizontal diametrical plane 1313 of the pump, but in 4 practice a relatively large play is used betwben the pump rotor and the beginning of the wall 12, so that in the known exhausters, the end edge of the outer wall lies about at 6070 and in the present invention appropriately at a somewhat smaller distance, such as for example about 50, displaced in the direction of rotation (in a clockwise direction) of the rotor 6 and about at the level of the outer edge of the reinforcing ring 8 as indicated at 14. In a normal air pump of this type, the outer wall 12 runs from the horizontal diametrical plane 13-43 tangentially straight upwardly and a parallel inner wall for the delivery channel is arranged so that the delivery channel extends to about 360. With the present construction, however, the delivery channel runs still further in a spiralshape to 90 and therefore extends 450 around the spindle of the rotor and only thereafter, starting from a vertical diametrical plane 15-15 through the pump spindle, outer wall 12a of the pump housing extends further horizontally to outlet 16, which is arranged in a tangential vertical end wall 17 at the right of the housing. At a definite distance from the outer edge 12a of the outlet 16, a bridging member 18 is arranged which lies parallel to the outer wall of the delivery channel and on and which a separating wall 19 is fixedly arranged which projects inwardly.

The distance from the upper edge of the bridging member 18 or from the upper face of the separating wall 19 to the wall 12a is selected so that by virtue of the separating wall about 15-20% of the total passing air stream is allowed to pass at that side. The rest of the air stream is carried away along the inner side of the separating wall 19 and the bridging member 18 through under portion 16b of the outlet opening which is delimited at the under side by an inner wall 20.

At the inner end of the separating wall 19 a further extension 21 is arranged rotatably on a spindle 22. The extension 21 can be adjusted from the outside with the aid of a grip (not shown) and fixing means, comprising a fixing bow or segment 23, at a desired branching percentage lying between about 10-25% through the delivery opening 16a. The openings 16a and 16b are provided with upstanding edges 24 and 25, to :which in practice the pipes to the final separator (cyclone) and the dust filter respectively (not shown) can be connected. The end separator can, as the amount of air to be worked is relatively small, be correspondingly small, as well as the filter because with the present air pump as experiments have shown, practically all impurities are carried away through the outlet 16a. The whole installation is accordingly quite simple and capable of being examined, while fully satisfying the requirements imposed thereon. A particular advantage of the invention is that it is not necessary to build the entire installation together, such 'as the air pump, the store room, the dust filter and the final separator, but such parts may all be arranged at an arbitrary adeqaute location.

This invention is not to be confined to any strict conformity to the showings in the drawings but changes or modifications may be made therein so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.

What is claimed is:

1. An installation for aspirating and separating waste products of working machines and more particularly wood working machines in which air is employed as a transport medium, comprising a housing, a centrifugal air moving means mounted within the housing, said housing having an inlet opening through which air and waste products are drawn into the housing from the working machines, said housing including wall means defining a spiral-shaped widening delivery channel extending perpendicular to the axis of the air moving means, said delivery channel being located behind the air moving means and provided with an outlet, said delivery channel being extended beyond the beginning thereof to such an extent that the particles to be separated and displaced at such location can separate and group together according to their Weight so that the separation of a quantity of transport air containing relatively heavy waste products occurs in the outlet, a separating Wall extending inwardly in th outlet of the delivery channel Serving to separate a small part of the passing air stream flowing along the outer wall of the delivery channel and which contains the most impure air, an adjustable hinged bafile at the free end of the separating wall, said separating wall being so arranged that it leads an amount of approximately -25 percent along the outer wall of the delivery channel to a final separator, and said air moving means being a centrifugal air pump so that a definite percentage of air passing along the outside of the delivery channel is separated from the remainder of the air stream.

2. The installation for aspirating and separating waste products of working machines as claimed in claim 1 in which said air moving means is a centrifugal air pump so that a definite percentage of air passing along the outside of the delivery channel is separated from the remainder of the air stream.

3. The installation for aspirating and separating waste products of Working machines as claimed in claim 1 in which said delivery channel extends about 450 around the axis of the air pump and the outer wall continues tangentially, and a bridge strip is fixed between the tangential end portion and the curved wall of the channel at the inside thereof for supporting the separating wall.

4. The installation for aspirating and separating waste products as claimed in claim 3 in which the starting point of the spiral-shaped delivery channel is displaced at an angle of about 35-50 in the direction of the air stream with respect to the theoretical starting point.

5. An installation for aspirating and separating waste products of working machines and more particularly wood working machines in which air is employed as a transport medium, comprising a housing, a centifugal air moving means mounted within the housing, said housing having an inlet opening through which air and waste products are drawn into the housing from the working machines, said housing including wall means defining a spiral-shaped widening delivery channel extending perpendicular to th axis of the 'air moving means, said delivery channel being located behind the air moving means and provided with an outlet, said delivery channel being extended beyond the beginning thereof to such an extent that the particles to be separated and displaced at such location can separate and group together according to their weight so that the separation of a quantity of transport air containing relatively heavy waste products occurs in the outlet, a separating Wall in the outlet of the delivery channel serving to separate a small part of the passing air stream flowing along the outer wall of the delivery channel and which contains the most impure air, said separating wall being so arranged that it leads an amount of approximately 10-25 percent along the outer wall of the delivery channel to a final separator, said separating Wall extending inwardly, and an adjustable hinged baffie provided at the free end of the separating wall.

References Cited UNITED STATES PATENTS 449,743 4/ 1891 Landis 230-47 2,282,015 5/ 1942 Williams. 2,289,474 7/ 1942 Anderson -393 FOREIGN PATENTS 418,544 9/ 1925 Germany. 105,617 7/ 1924 Switzerland. 218,097 7/ 1924 Great Britain. 236,452 7/1925 Great Britain. 502,158 7/1930 Germany.

HENRY F. RADUAZO, Primary Examiner.

U.S. Cl. X.R. 

